1. Field of the Invention
The present invention relates to a surface fastener made of fiber comprising at least a large number of engaging elements woven/knitted into a surface of a woven/knitted fabric obtained by weaving/knitting, the engaging elements being woven/knitted simultaneously with weaving/knitting of the woven/knitted fabric, and to a method for manufacturing the fastener.
2. Description of the Related Art
The surface fastener of this type generally comprises a male engaging member having a large number of hook-shaped or mushroom-shaped male engaging elements formed to stand on a surface of a flat substrate and a female engaging member having a large number of loop-shaped female engaging elements rising in close contact with each other on a flat substrate. By setting the female and male engaging members with their faces on which the engaging elements are formed facing each other and by pushing the male and female members against each other, the male and female engaging elements are engaged with each other to join the male and female engaging members to each other. By peeling the male and female engaging members from each other, the engaged male and female engaging elements are detached from each other.
The surface fastener having the above structure is applied to extremely many fields from daily necessities to industrial material. In recent years, a molded surface fastener made of synthetic resin and obtained by integrally and simultaneously molding fine male engaging elements and a flat substrate has taken the place of a woven or knitted surface fastener and has been put to actual use. The molded surface fastener has been used as fasteners of various diapers and sanitary napkins which are liable to be in direct contact with user's skin.
The most general structure of the female engaging member to be engaged with and detached from the male engaging member is a so-called pile woven/knitted fabric having a large number of loops formed to stand on a ground structure of the woven/knitted fabric made of fiber. The piles (loops) are usually obtained by weaving or knitting multifilament into the ground structure of the pile woven/knitted fabric. As another type of female engaging member, a general nonwoven cloth having a surface dense with fine piles has come to be used, as the above fine engaging elements of the integrally molded surface fastener has been put to actual use.
As warp and weft constituting yarns of a substrate woven/knitted fabric for weaving, fixing, and supporting the male or female engaging elements, a twine made of multifilament or a normal spun yarn is used. A purpose for this is to further firmly hold monofilament or multifilament forming the male or female engaging elements by a weaving/knitting structure formed of warp and weft and to prevent the engaging elements from falling out of the substrate, by utilizing a friction force of a rough surface of the twine and flexibility of the twine in a shearing direction. Therefore, a density of weaving of the substrate is naturally set at a large value.
Japanese Patent Publication No. 55-38121 discloses an example wherein the loops as the female engaging elements are formed of a single yarn of 90 d made of the twine of multifiber. In a surface fastener disclosed in this Japanese Patent Publication, warp and weft constituting yarns of the ground structure of the woven fabric are formed of twines made of multifiber. A single rubber yarn is used as a part of the warp, and the ground structure is woven while stretching the rubber yarn. The loops as the female engaging elements and the loops to be used for the hooks as the male engaging elements are firmly tied and fixed to the ground structure by contraction of the woven rubber yarn when weaving is finished.
On the other hand, the variety of use of the surface fastener of this type is further increased. In the same industrial field, there is a strong need for a surface fastener which fits for material, a structure, or a color of clothes in a field of clothes, for example, wherein a fashion sense is required. Particularly, the surface fastener has recently come to be used frequently not only for underwear but also for outerwear. In thin clothes made of a lace fabric, for example, the surface fastener itself is required to be thin and to have transparency and flexibility throughout the fastener so as to be adapted to the material or structure of the clothes. Further, in addition to the above needs, there is a need for a surface fastener which is thin and has a strong engaging force in a large field of engaging and detaching devices for various outerwear and bags, for example. Also, in a fastener portion of various sportswear and bags, for example, it is required to see and recognize various designs and colors of a logotype and the like on the clothes or bags through the surface fastener, even if the fastener is thick.
In the surface fastener disclosed in the above Japanese Patent Publication, however, the density of weaving of the substrate is increased by using the rubber yarn, and the majority of the used yarns is twine. Therefore, it is impossible to obtain a thin and flexible surface fastener. In addition, as is apparent from another example disclosed in the above Japanese Patent Publication, a large number of piles are densely formed to stand on the surface of the flat substrate made of fiber particularly in the female engaging member of the conventional surface fastener, as described above. As a result, a rear side of the surface fastener can not be seen through due to the piles densely formed on a front face of the fastener, and this defect can not be overcome even if any thought is put into designing the flat substrate.
Therefore, conventionally, desired designs, letters, or marks are applied to a surface of a product including a surface of a surface fastener after the fastener is mounted to the product, or necessary designs are applied to the surface of the surface fastener in advance. In the former case, various problems based on a difference in dyeing properties of the surface fastener and a member of clothes and the like to be mounted with the fastener are liable to be generated, and in addition, two steps of operation are required to apply designs and the like. In the latter case, a number of steps is increased, and in addition, positioning of the designs on the surface fastener to the designs on the product in mounting of the fastener is complicated, thereby significantly decreasing a producing efficiency. Furthermore, shapes of the designs on the pile face are easily deformed, the designs on the pile face may be displaced from the designs on the clothes body over time, and a difference in clearness of colors of designs on the clothes body and the fastener is liable to be generated.